,-%  A,        \     - 


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K 

UNION    PACIFIC    RAILROAD 


REPORT  OF  F.  M.   CASE, 


burtons  of  Caclje  |Te  foutoe  £  So.ut|  f  latte  pontes, 


OTHER  MOUNTAIN  PASSES  IN  COLORADO. 


Omaha,  Neb.  T'y,  Dec.  15, 1864. 

Sir, — Under  my  instructions  to  gather,  by  actual  survey  and 
otherwise,  whatever  information  I  could  relating  to  the  moun- 
tain passes  of  Colorado,  I  have  the  honor  to  submit  the  followT- 


REPORT. 

These  passes,  or  such  of  them  as  have  been  spoken  of  as  pos- 
sible or  practicable  for  railroad  purposes,  are,  the  Cache  La 
Poudre,  the  Boulder,  the  Berthoud,  a  pass  at  the  head  of  the 
North  Fork  of  the  South  Platte,  one  at  the  head  of  Tarryall 
creek,  and  the  Hoosier  Pass  near  Montgomery. 


THE   BOULDER   PASS. 


From  information  obtained  from  Mr.  D.  C.  Collier,  a  very 
intelligent  explorer  of  Colorado,  and  now  editor  of  the  Miners' 
Register,  of  Central  City,  and  from  other  sources,  I  judge  the 
Pass  to  be  at  least  $11,900  feet  above  the  level  of  the  sea.     The 


valley  (of  S.  Boulder,)  at  the  foot  of  the  mountains  cannot  be 
more  than  5,600  feet.  The  elevation  of  Boulder  City,  six  miles 
north,  on  North  Boulder,  being  5,536  feet.  This  leaves  a  dif- 
ference of  elevation  of  6,300  feet,  and  this  elevation  must  be 
overcome  in  a  distance  at  most  of  35  miles.  Knowing  these 
facts,  I  have  not  even  visited  the  Boulder  Pass. 


Would  enter  the  mountains  at  the  caiion  of  the  South  Platte, 
follow  np  that  stream  about  10  miles  to  the  mouth  of  the  North 
Fork,  tlience  up  that  stream  35  miles  to  the  range,  and  thence 
connect  with  one  of  the  heads  of  Snake  river,  an  affluent  of  the 
Blue.  The  pass  is  represented  by  Hon.  Daniel  Witter,  another 
very  intelligent  explorer  of  Colorado,  as  being  a  little  below  the 
"  timber  line,"  probably  about  11,500  feet  above  tide-water. 
From  elevations  kindly  furnished  me  by  Dr.  C.  C.  Parry,  I  am 
enabled  to  give  some  information  that  may  be  of  use  in  judging 
of  this  route.  At  a  point  12  or  15  miles  below  the  pass  ("  The 
Forks,")  the  elevation  is  9,153  feet,  at  7  miles  below  it  is  8,405, 
and  at  a  point  4  miles  further  down  8,018,  indicating  that  a 
practical  grade  would  follow  the  valley  to  "  The  Forks."  The 
trouble  I  apprehended  would  be  to  overcome  2,300  feet  eleva- 
tion in  the  12  or  15  miles  from  that  point  to  the  pass,  without  a 
very  long  tunnel. 

The  descent  upon  the  western  slope  to  the  mouth  of  Snake 
river,  a  distance  of  not  more  than  20  miles,  is  2,700  feet,  upon 
the  hypothesis  that  the  pass  is  11,500  feet  above  tide-water. 
The  route  for  the  entire  distance  from  the  plains  to  the  Bine  is 
through  a  narrow  valley,  and  in  many  places  doubtless  very 
tortuous. 

THE  TARRYALL  CREEK  ROUTE 

Enters  the  mountains  via  South  Platte,  and  follows  up  the  main 
stream  10  or  12  miles  further  than  the  last  mentioned  route, 
where  it  diverges,  following  up  the  valley  of  Tarry  all  creek  some 
25  miles  to  the  South  Park,  thence  near  the  creek  across  the 
Park  to  Hamilton  and  Tarryall,  thence  up  the  main  stream  to 


a  pass  about  the  height  of  Hoosier  Pass,  from  which  it  descends 
Indiana  Gulch  to  the  Blue  above  Breckenridge. 

Of  this  route  I  can  say  but  little  advisedly.  Dr.  Parry  gives 
the  elevation  of  Tarryall  (old  town)  at  9,932  feet.  The  pass, 
at  a  distance,  in  my  opinion,  not  exceeding  six  miles,  is  1,500 
feet  higher.  I  do  not  think  that  the  maximum  grade  allowed 
by  the  charter  would  go  within  two  miles  of  the  pass,  following 
the  stream.  Whether  there  is  any  way  of  making  distance  on 
this  approach  or  not  I  cannot  tell,  as  I  have  not  had  an  oppor- 
tunity of  examining  the  route  from  Tarryall  to  the  pass.  I  have 
been  down  Indiana  Gulch  to  the  Blue,  and  should  say  the  des- 
cent was  150  or  200  feet  to  the  mile. 


THE  SOUTH  PLATTE  ROUTE. 

I  have  made  a  partial  survey  of  this  route,  and  report  here- 
with a  profile  of  Hoosier  Pass,  a  profile  of  a  line  18  miles  down 
the  Blue,  and  one  of  a  line  48  miles  down  the  South  Platte, 
through  the  South  Park  to  the  head  of  the  canon. 

A  tunnel  of  2  J  miles  in  length  would  be  required  at  the  cross- 
ing of  the  range.  This  tunnel  would  be  through  granite  the 
entire  distance,  and  would  doubtless  cross  several  gold  lodes, 
which  crop  out  upon  the  western,  or  rather  northern  slope. 

The  line  upon  the  western  slope  would  have  to  follow  the  side 
of  the  mountain  to  get  a  practical  grade.  I  should  think  dis- 
tance sufficient  could  be  gained  upon  the  east  side  of  the  Blue 
to  allow  the  grade  to  reach  the  valley  a  few  miles  below  Brecken- 
ridge, from  which  point  to  the  mouth  of  the  Blue  the  line  would 
follow  a  fine  wide  valley,  with  easy  grades,  as  indicated  by  the 
profile,  and  good  alignment ;  except  that  the  valley  makes  but* 
very  little  westing  in  its  entire  length. 

A  line  down  the  South  Platte  may  be  located  so  as  to  secure, 
very  nearly,  a  uniform  grade  from  the  mouth  of  the  tunnel  to 
the  head  of  the  canon,  where  my  line  terminates,  with  light 
curves  and  light  work,  as  the  profile  indicates. 

When  I  reached  the  head  of  the  canon,  I  found,  by  examina- 
tion, that  it  extended  9  or  10  miles,  and  there  being  no  way  of 
moving  camp  down  the  valley,  except  by  "  packing,"  I  concluded 


to  abandon  the  survey.  From  the  head  of  the  canon  to  the 
plains,  a  distance  of  some  40  miles,  the  river  runs  all  of  the  way 
through  the  mountains.  The  greater  portion  of  the  distance  the 
valley  is  of  sufficient  width  to  admit  of  a  good  location  for  the 
road,  but  there  would  probably  be  20  miles,  at  least,  of  "close  " 
canon,  or  one  both  walls  of  which  are  washed  by  the  stream. 
There  would  necessarily  be  a  good  deal  of  tunnelling  in  the 
canon — how  much  I  cannot  say.  I  estimated  the  height*  of 
Itoosier  Pass  to  be  11,500  feet  above  the  sea.  This  estimate  I 
formed  from  its  being  about  200  feet  below  the  limit  of  arbor- 
escence  or  "tree  line,"  which  in  that  locality  is  about  11,700 
feet  above  tide-water.*  Allowing  the  pass  to  be  as  estimated, 
the  elevation  at  the  head  of  the  canon  will  be  8,432  feet.  Call- 
ing the  mouth  of  the  canon  5,700,  it  would  leave  a  difference 
of  elevation  of  2,732  feet  between  the  mouth  of  the  canon  and 
its  head,  making  an  average  grade  of  less  than  70  feet  per 
mile. 

In  the  matter  of  grades,  I  do  not  hesitate  in  the  opinion  that 
there  is  no  route  in  Colorado  with  so  easy  an  approach,  on  both 
sides  of  the  main  range  of  mountains,  as  this  route.  Yet  the 
easy  grades  are  made  at  the  sacrifice  of  general  alignment. 
There  will  be  a  line  of  about  145  miles  in  length  to  make  76 
miles  of  westing  between  Denver  and  the  mouth  of  the  Blue. 

There  is  an  abundance  of  timber,  the  mountain  varieties  of 
fir,  spruce,  and  pine,  along  the  whole  route,  except  that  in  the 
Park  it  is  some  distance  from  the  line.  Good  building  stone 
and  limestone  may  be  easily  procured  from  the  ridges  of  strati- 
fied rock  that  intersect  the  Park,  and  in  the  same  formation  in 
the  valley  of  the  Blue. 

From  what  information  I  have  gleaned,  in  three  and  a  half 
years  residence  in  Colorado,  the  snow  falls  in  the  basin  of  the 
Blue  and  in  the  vicinity  of  Hoosier  Pass  deeper  than  in  any 
part  of  Colorado.  From  some  person  (I  cannot  now  remember 
who  gave  me  this  information,)  who  kept  a  meteorological  record 


*  I  have  since  learned  from  Dr.  Parry  that  the  "  tree  line  "  at  Georgia  Pass, 
the  nearest  point  to  the  Hoosier  Pass,  at  which  it  has  been  taken,  is  11,487  feet. 

F.  M.  C. 


at  Georgia  Gulch,  during  the  winter  of  1861-2,  I  learned  that 
the  total  fall  of  snow  at  that  place  was  37  feet ;  and  in  one  storm 
in  February,  1862,  11  feet.  Georgia  Gulch  is  on  the  western 
slope — one  of  the  gulches  of  Swan  river,  an  affluent  of  the  Blue. 

THE  BERTHOUD  PASS  ROUTE. 

I  did  not  have  time  to  make  any  further  examination  of  this 
route  the  past  season,  and  have  but  little  information  to  report 
that  is  not  contained  in  my  report  to  Gov.  Evans  in  1862. 
Which  report,  with  a  few  corrections,  such  as  further  experience 
in  the  geology  and  climatology  of  Colorado  dictates,  I  here  in- 
sert, that  I  may  embody  in  one  paper  all  the  information  I 
Tiave  been  able  to  obtain  upon  the  subject,  up  to  the  present 
date. 

"Colorado  Territory,        ) 
Denver,  August  15th,  1862.  ) 

"  Hon.  John  Evans,  Gov. 
Col.  Territory : 

u  Sir, — In  submitting  to  you  this  report  of  my  late  instrumental 
reconnoissance  of  the  Berthaud  Pass  and  its  eastern  approach, 
with  the  view  of  its  being  by  you  laid  before  the  Board  of 
Corporators  of  the  Pacific  Kaiiroad,  I  am  aware  that  the  facts 
which  will  be  of  real  interest  to  practical  railroad  men  are 
very  meagre  ;  yet,  as  many  misrepresentations  have  been  made 
upon  mere  opinion,  the  few  facts  I  have  gleaned  may  be  of  in- 
terest to  the  Board  of  Corporators,  of  which  you  are  a  member. 

"  I  have  had  a  connected  line  of  levels  run  from  the  Platte 
River  (at  the  upper  bridge  in  Denver)  to  the  summit  of  the 
Pass  and  two  and  three  fourths  miles  down  Moses  Creek,  on  the 
Pacific  slope.  From  one  mile  below  Empire  City  a  transit  line 
has  been  run  over  the  Pass — levels  have  been  run  up  Clear 
Creek,  a  mile  and  a  half  above  the  mouth  of  Hoope's  Creek, 
opposite  the  pass,  and  also  from  Empire  City  to  the  low  pass 
between  Bard  Creek  and  the  south  fork  of  Clear  Creek.  Be- 
tween this  low  pass  and  Georgetown,  one  and  three-fourths  mile 
south,  the  relative  elevations  have  been  ascertained  by  barometric 


6 


observations,  by  Dr.  Parry,  a  gentleman  who  is  spending  the 
summer  near  the  Range,  making  scientific  explorations. 

"  I  submit  herewith  a  map  of  the  route  from  Denver,  west- 
ward, embracing  the  Pass,  giving  a  very  fair  representation  of 
the  topography  of  the  country  in  the  vicinity  of  the  Pass,  with 
the  relative  elevations  at  certain  points,  as  ascertained  by  the 
levels.  Upon  this  map  I  have  drawn  a  proposed  location  of  a 
railroad  line,  which,  in  my  opinion,  will  be  near  the  most  prac- 
ticable route  for  the  real  location.  The  length  of  the  tunnel  I 
make  three  and  a  half  miles.  I  have  made  this  length  by  sup- 
posing an  up-grade  of  fifty  feet  to  the  mile,  running  westward 
in  the  tunnel  from  the  entrance,  for  two  miles,  and  thence  runT 
ning  a  down  grade  of  ten  feet  to  the  mile,  to  the  exit. 

"  An  up  grade  in  the  tunnel  of  one  hundred  feet  to  the  mile 
for  the  first  two  miles,  instead  of  fifty,  would  shorten  the  tunnel 
about  one-fourth  of  a  mile.  The  grade,  as  you  will  notice,  is 
less  than  116  feet  to  the  mile  from  the  forks  below  Empire  City 
to  the  tunnel,  but  the  equation  for  curvature,  on  the  line  1  have 
drawn,  would  probably  bring  the  grade  up  to  this  maximum. 

"  This  range  of  mountains,  on  its  eastern  slope  being  subject  to 
a  very  considerably  less  fall  of  rain  during  the  year  than  the 
Alleghanies  or  ]STew  England  mountains,  are  much  less  dis- 
integrated, and  are  fitly  called  "  Rocky  Mountains."  The  moun- 
tains on  either  side  of  the  valley  of  Clear  Creek  are  "  rugged," 
with  frequent  points  of  rocks  projecting  into  the  valley  ;  for  this 
reason  I  have  drawn  the  line  so  as  to  get  down  into  the  valley 
with  the  grade  as  soon  as  possible. 

•'  I  might  say  in  this  connection,  that  there  would  be  a  possi- 
bility of  striking  rich  gold  lodes  in  the  construction  of  the  tun- 
nel, for  it  is  in  the  "  Gold  Belt."  there  being  lodes  on  each  side 
of  the  pass,  yet,  I  would  not  like  to  undertake  the  construction 
of  the  tunnel  with  the  understanding  that  I  should  take  this 
"  possibility"  in  "  part  pay." 

"  Of  the  Western  approach  to  the  Pass  I  will  hazard  no  opinion 
as  to  gradients  or  courses.  The  Western  slope  of  the  Range 
seems  to  be  covered  with  a  much  deeper  soil,  as  it  is  covered 
with  a  much  denser  foliage,  which  is  doubtless  owing  to  the 
arrest  and  precipitation  of  the  spring  and  summer  rains  by  the 
snow  of  the  Range ;  the  prevailing  winds  being  northwesterly. 


This  fact,  in  case  of  having  to  keep  the  mountain  sides  to  get 
down  to  the  valley  of  the  Grand  River,  would  render  the  cost 
of  construction  much  less  than  upon  the  Eastern  Slope. 

"  I  have  made  considerable  inquiry  as  to  the  winter  snows  in 
the  neighborhood  of  the  Pass,  and  find  that  at  Empire  City, 
they  have  wintered  cattle  every  winter  without  hay.  From 
all  the  statements  of  settlers  on  the  experience  of  three  winters, 
I  am  of  opinion  that  the  winter  snows  would  form  no  serious 
obstacle  to  the  running  of  railroad  trains  from  the  tunnel  east- 
ward. About  three-fourths  of  a  mile  from  the  Pass,  on  the 
western  slope,  we  passed  a  camp  where  a  family  were  snow- 
bound last  winter,  for  some  weeks,  and  judging  from  the  height 
of  the  stumps  of  trees  cut  by  them  while  there,  should  think 
the  snow  must  have  been  five  or  six  feet  deep.  This  depth, 
from  all  the  information  I  can  glean,  would  be  about  a  fair 
average  for  about  fifteen  or  twenty  miles  west  of  the  Range,  in 
the  vicinity  of  the  Pass.  The  prevailing  winds  being  from  the 
northwest,  the  snow  piles  in  immense  drifts  on  the  southeastern 
slopes  of  the  range.  These  slopes,  in  the  vicinity  of  the  Pass, 
being  very  precipitous  near  the  summit,  arrest  the  snows  before 
they  reach  the  valley  of  Clear  Creek.  This  fact  may  account 
for  the  light  fall  of  snow  near  Empire  City. 

"  The  following  table  will  show  very  nearly  the  distances 
between  the  points  at  which  I  have  ascertained  the  elevations 
above  the  Platte  at  Denver,  along  the  proposed  route  from 
Denver,  westward  to  the  Pass  : 

Places.  Distances.  Elevation. 

Platte  River,  a,t  Denver.. 0  miles.       0. 

Divide  between  Denver  and  Golden  City. . .     7.5  "  544. 

Golden  City 5.0  "  500. 

Ten  miles  up  the  Canon 10.0  "  1580. 

Where  Idaho  road   enters  valley  of  Clear 

Creek. 0.8  "  2019. 

Idaho 5.2  "  2395. 

Forks  of  Clear  Creek  below  Empire  City. . .     7.3  "  3117. 

Georgetown 4.0  "  3519. 

Entrance  of  Tunnel 13.0  "  4820. 

Total  distance  from  Denver 57.8     " 


8 

u  In  entering  the  Canon  of  Clear  Creek,  either  from  Denver 
or  the  month  of  Clear  Creek,  the  road  can  go  into  the  Canon 
from  one  to  five  hundred  feet  above  the  water  of  the  creek,  if 
a  better  line  can  be  found  at  such  elevation. 

"  Of  the  cost  of  construction  of  a  railroad  from  Golden  City 
to  the  entrance  of  the  tunnel,  I  cannot,  of  course,  make  an 
estimate  upon  this  reconnoissance,  but  should  say  the  expense 
would  not  be  greater  than  the  average  of  eastern  mountain 
roads  for  the  same  distance. 

"  Hoping  these  few  facts  may  be  of  service  to  you  and  the 
Board  of  Corporators  of  the  Pacific  Railroad,  I  am, 
"  Very  truly  your  obedient  servant, 

"  Francis  M.  Case, 

Civil  Engineer." 

Since  writing  the  foregoing  report  I  have  obtained  from  Dr. 
Parry  the  elevation  of  the  head  of  Middle  Park,  about  ten 
miles  from  the  pass  on  the  western  slope,  which  is  8,949  feet,  or 
1,340  feet  lower  than  the  mouth  of  the  proposed  tunnel  7i  miles 
above.  The  Hot  Springs  on  the  Grand  river,  20  miles  farther 
down,  he  makes  7,546  feet,  showing  an  average  grade  from  the 
head  of  the  park  to  the  Hot  Springs  of  about  70  feet  to  the 
mile. 

There  is  one  difficulty  that  would  be  encountered  upon  this 
route  not  mentioned  in  the  above  report,  and  that  is  in  the 
form  of  avalanches  or  glaciers,  which  occur  occasionally  at 
two  different  points  near  the  foot  of  the  pass,  upon  the  moun- 
tain side  south  of  Clear  creek.  The  mass  of  snow  and  ice  which 
accumulates  at  the  head  of  gulches  at  these  points,  loosening 
next  to  the  mountain  by  the  action  of  the  water  from  the  melt- 
ing snows,  sweeps  down  the  mountain  side  with  a  velocity  that 
carries  everything  before  it.  At  the  one  above  the  mouth  of 
Hoope's  creek,  I  saw  trees  and  rubbish  which  had  been  driven 
before  the  avalanche  across  the  creek,  and  four  or  five  hundred 
feet  up  the  northern  slope  of  the  valley.  A  located  line  would 
cross  the  track  of  both  these  avalanches. 

THE  CACHE  LA  POUDRE  ROUTE. 

Over  this  route  I  have  run  a  preliminary  line,  commencing  at 


La  Porte,  and  running  as  indicated  by  the  red  line  upon  the  ac- 
companying map,  I  connected  with  Mr.  Evans'  line  at  his  station 
1,360,  near  the  crossing  of  Laramie  river. 

Being  entirely  unacquainted  with  the  topography  of  the 
country  along  this  route,  I  kept  my  line  in  the  valley  of  streams 
until  1  passed  Cherokee  station,  and  thence  along  what  appeared 
at  first  sight  to  be  the  most  feasible  route.  My  party  being 
short  I  was  obliged  to  be  with  them  so  much  that  I  could  not 
devote  as  much  time  to  reconnoissance  as  I  otherwise  would. 
I  very  much  regret  that  I  had  not  time  to  run  a  new  line  nearly 
or  quite  the  whole  distance  from  La  Porte  to  the  summit ;  and 
also  to  try  a  line  over  the  divide  to  the  head  waters  of  Crow 
creek.  I  think  I  can  get  a  fair  line  with  lighter  grades  from  La 
Porte  to  the  Laramie  Plains  than  are  shown  by  any  line  yet  sur- 
veyed over  the  Black  hills.  Yet  this  is  only  my  opinion.  An 
actual  survey  only  will  determine  this  point.  Some  points  are 
already  settled  by  the  present  survey.  One  is,  that  Antelope 
Pass  is  593  feet  lower  than  the  summit  made  upon  the  Cheyenne 
Pass  route.  Another  is,  that  the  descent  to  the  Laramie  Plains 
from  Antelope  Pass  may  be  made  with, a  grade  not  much,  if  any, 
exceeding  80  feet  per  mile. 

I  have  indicated,  by  a  red  dotted  line  upon  the  map,  my  pro- 
posed location.  I  think  a  line  may  be  obtained  with  a  practical 
grade  by  keeping  in  a  valley  to  the  right  of  the  stage  road,  and 
coming  into  the  road,  or  near  it,  above  Boner  station.  If  so,  it 
would  be  very  much  preferable  to  any  line  following  the  Cache 
La  Poudre  and  Dale  creeks.  For  those  valleys  being  so  narrow 
the  grade  must,  of  necessity,  be  laid  at  least  25  feet  above  the 
bed  of  the  stream.  Evidences  of  the  flood  of  last  spring  show 
that  the  water  was  20  feet  above  its  present  stage. 

If  this  route  should  be  found  to  be  impracticable,  I  would  try 
a  route  as  indicated  by  the  westerly  dotted  line  passing  over  (or 
rather  going  through  with  a  thousand  feet  tunnel)  a  low  pass, 
about  opposite  the  junction  of  Dale  and  Cache  La  Poudre  creeks, 
and  keeping  along  the  eastern  slope  of  the  valley  of  Dale  creek 
join  the  other  line  near  the  crossing  of  Stonewall  creek.  From 
this  point,  I  think,  by  keeping  up  the*divide  west  of  this  creek, 
the  line  would  enter  Stonewall  canon  at  a  height  sufficient  to  get 
a  fair  line  through  the  canon,  and  reach  an  elevation  at  its  head 


10  MR.    CASE'S    REPORT. 

which  would  admit  of  getting  up  the  divide  beyond  and*near 
the  stage  road  with  a  grade  not  exceeding  2.2  feet  per  station. 

Much  time  and  care  should  be  bestowed  upon  a  located  line, 
as  the  country,  especially  from  Poison  creek  to  the  pass,  is  very 
rough,  broken  by  points,  and  ledges  of  granite  thrown  up  pro- 
miscuously. In  some  places  you  see  only  bare  and  isolated  peaks, 
in  others,  ledges,  trending  in  every  conceivable  direction. 

In  this  connection  allow  me  to  suggest  that  a  thorough  exam- 
ination should  be  made  of  the  divide,  east  of  Dale  creek,  and  a 
few  miles  north  of  Virginia  Dale,  at  the  heads  of  Crow  creek 
and  Box  Elder.  From  what  information  I  can  get,  the  foot  of 
the  mountains  east  of  this  point  is  as  high,  or  even  higher  than 
the  starting  point  of  Mr.  Evans'  line.  That  point  is  1,953  feet 
higher  than  my  starting  point  at  La  Porte.  Now,  if  by  some 
branch  of  Crow  Creek  or  Howard's  Fork,  we  can  find  a  uniform 
grade  to  the  summit,  I  think  such  grade  will  be  within  the  limit 
fixed  by  the  charter  of  the  road.  By  reference  to  the  map  you 
will  see  that  such  a  route  would  connect  with  a  line  up  the 
South  Platte,  with  a  much  better  general  alignment  than  by  La 
Porte;  or  would  connect  "with  the  Lodge  Pole  Route,  by  way 
of  Muddy  Fork,  without  a  serious  sacrifice  of  alignment.  [See 
also  Stansbury's  Report,  p.  258,  et  seq.~\ 

If  a  route  can  be  obtained  up  the  valley,  east  of  Boner  station 
near  the  line  I  have  drawn,  it  would  pass  over,  from  La  Porte 
to  Stonewall  Canon,  soil  that  is  underlaid  by  stratified  rocks, 
with  occasional  outcrops  of  the  latter.  From  Stonewall  Canon 
to  Laramie  Plains,  the  formation  is  all  primitive  ;  most  of  the 
way  however,  the  surface  is  covered  with  a  soil — the  result  of 
the  disintegration  and  decomposition  of  the  granitic  rocks.  In 
the  Stonewall  canon  the  granite  is  close  grained,  hard,  and  in- 
tersected by  veins,  or  dykes  of  some  basaltic  rock.  Toward  the 
Laramie  Plains,  the  feldspar  predominates,  rendering  the  rock 
more  friable,  and  susceptible  to  disintegrating  agencies. 

As  far  as  my  observation  extended,  the  primitive  formation 
along  the  route  shows  no  traces  of  any  mineral  veins  whatever. 
My  2d  assistant,  Mr.  Pirn,  says  there  is  no  doubt  that  Rock 
creek,  furtherwest,  comes  vdown  from  a  gold  region.  That  he 
has  seen  the  evidences  himself;  and  also  assured  me  that  there 


MR.    CASE'S    REPORT.  11 

was  a  large  body  of  iron  ore  in  the  vicinity  of  our  line,  (he  would 
not  say  where,)  that  he  had  also  seen  himself. 

I  did  not  see  any  indications  of  coal,  in  the  later  formations 
along  the  route.  I  did  not  look  for  them  in  the  vicinity  of  the 
primitive  rocks,  believing  that  coal  will  not  be  found  in  such 
localities.  The  intense  heat,  at  some  period  of  'their  geological 
history,  having  driven  off,  or  consumed  the  carbon,  if  it  were 
ever  there. 

There  is  a  sparse  growth  of  timber,  in  places  along  the  route, 
mostly  a  dwarfed  variety  of  pine.  South  of  the  line,  and  at  no 
great  distance,  appears  to  be  a  heavy  growth  of  good  timber. 

I  think  there  would  be  little  difficulty  in  rafting  timber  down 
the  Cache  La  Poudre,  and  less  still  in  getting  it  down  the  Big 
Laramie. 

Accompanying  this  report  I  have  the  honor  to  submit  con- 
densed profiles  of  the  Cache  La  Poudre,  the  Berthoud,  and  the 
South  Platte  routes.  These  profiles  are  made  from  my  own 
*—-  surveys,  and  from  such  other  data  as  I  have  been  able  to  obtain. 
The  grades  in  these  profiles  are  broken  to  show  the  general  un- 
dulations of  the  surface  only.  I  also  submit  maps  of  the  lines 
run  during  the  past  season,  together  with  a  map  of  Colorado, 
showing,  approximately,  all  the  different  routes. 

I  have  made  no  'estimate  of  quantities  upon  any  of  these 
routes,  for  the  reason  that  as  yet  1  have  not  had  time  to  run  a 
line  approximating  the  best  location  sufficiently  near  to  make 
an  estimate  upon. 

Respectfully  submitted, 

FRANCIS  M.  CASE, 

Div.  Engr. 
To  T.  C.  Dcrant,  Esq., 

Vice-PresH  U.  P.  B.  R.  Co., 

No.  13  William  st.,  New  York. 


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